The present invention relates to a burglarproof device of a vehicle which controls a drive of a steering-lock actuator for selectively taking a steering lock state or a steering unlock state.
Installing a smart key-less entry system to vehicles, such as automotive vehicles, has been recently proposed for improvements of operability. The smart key-less entry system enables a door lock or unlock by operating a switch provided at or near an outer handle of a vehicle door when a portable device is carried by a vehicle passenger, or an engine start or stop by operating a push or rotational type of ignition switch provided in a vehicle compartment when the portable device is in the vehicle compartment.
Meanwhile, the vehicles are equipped with a steering lock mechanism to improve the vehicle burglarproof function. The steering lock mechanism prevents a rotational operation of a vehicle steering when the vehicles are parked. In the steering lock mechanism of the vehicles equipped with the above-described smart key-less entry system, a lock member operative to engage with or disengage from a steering shaft is driven by an actuator for steering lock. The drive of the actuator is controlled by a controller such that the lock member selectively takes a steering lock state or a steering unlock state (see Japanese Patent Laid-Open Publication Nos. 2001-1865, 2003-293923, for example).
Herein, the steering-lock actuator of the above-described burglarproof device may produce a relatively large drive noise (sound). Accordingly, it may be preferable in order to make this drive noise quite that the lock member be configured to selectively take the steering lock state or the unlock state at the time the door is opened or closed (the door state changes from the open state to the closed state, or its reverse) or the state of the door lock or unlock changes. Thus, the changing timing of making the lock member taking the steering lock state from the unlock state may overlap with the timing when the change in the door state, such as the door opening-closing state or the door lock-unlock state, is detected while the ignition switch is in an OFF state.
Further, it may be required from the safety point of view that the lock member be changed so as to take the steering lock state from the steering unlock state on condition that the vehicle stops. Thus, it may be preferable that the lock member be changed so as to take the steering lock state from the steering unlock state if the change in the door state is detected and the vehicle stop state is detected when the ignition switch is in the OFF state.
Herein, the vehicle stop state may be detected by a general vehicle speed sensor. Or, that state may be detected by a vehicle detecting device which is provided in a device or system (an anti-lock brake system, for example) which is different from the burglarproof device. In the latter manner, cost reductions may be achieved.
However, according to the above-described changing of the timing to the steering lock state, since it may be required that the above-described vehicle speed sensor, device, or system be made in an operational mode even while the ignition switch is the OFF state, there is a problem in that the so-called dark current would improperly increase because the small amount of power supply to these sensor, device or system continues during the time the ignition switch is the OFF state. If the ignition-switch OFF state was prolonged improperly because of a driver's taking a nap or the like without operating the door, this problem would be serious. Particularly, in a case in which the vehicle-speed detection by the vehicle speed device of the above-described device or system different from the burglarproof device is applied, the above-described dark current would tend to increase further greatly.